What version of OpenGL does Blender use?
Blender requires OpenGL 3.3, however we may take advantage of newer OpenGL versions too.

So while Blender depends on 3.3, it may use newer features when available and fail gracefully if they are not (as opposed to crashing or not starting at all).

Note that some features are user preferences too since we can't always rely on asking the driver if a certain feature works well or not (drivers don't always give us reliable information).

See: https://www.blender.org/download/requirements/